Answer:
60
Step-by-step explanation:
let a = 22 / kg, and b = 12 / kg
a + b = 20 kg
22a + 12b = 15 * 20
12a + 12b = 240
10a = 60
it is correct
shown above in the photo
the answer is 6x-7
3x-4+2-2x-5+5x
3x-7-2x+5x
3x-7-2x+5x=
6x-7